Cellular networks are increasingly using satellite communication systems to carry cellular backhaul traffic between an Evolved Node B (eNodeB, or eNB) and Evolved Packet Core (EPC) in LTE networks. Such satellite backhaul networks carry traffic from various applications such as Web Browsing, VoIP (voice over IP), audio and video streaming, etc. The satellite backhaul network also carries signaling packets between eNodeB and EPC. For over the air security between the eNodeB and mobile devices, user data and control signal messages are encrypted. On the internet protocol (IP) network, IP security (IPsec) is usually employed between the eNodeB and the EPC.
In order to optimize the use of available bandwidth, satellite networks typically provide quality of service (QoS) based prioritization, transmission control protocol (TCP) acceleration, etc. Satellite networks can also implement efficient ways of carrying traffic over satellite link, such as header compression and data compression. Such techniques and services, however, require that the very small aperture terminal (VSAT, or simply terminal) and the gateway are capable of identifying the traffic type of traffic being exchanged. Thus, it would be possible for the terminal and gateway to treat the traffic in accordance with their characteristics. For example, the satellite system could provide high priority treatment for real-time traffic such as voice communication that is very sensitive to latency. Conversely, traffic such as web browsing can be treated as low priority.
General Packet Radio Service (GPRS) tunneling protocol (GTP) acceleration has been developed to improve cellular traffic being carried over the satellite network. GTP acceleration is applied to cellular traffic between eNodeB and EPC that is flowing in the GTP tunnel of the satellite network. The GTP Acceleration can provide, for example, GTP tunnel header reduction, TCP acceleration, data compression, and QoS-based traffic prioritization, etc. Secure cellular traffic, however, utilizes IPsec to protect the traffic between eNodeB and EPC. Consequently, the terminal and gateway will not be able to determine the type of traffic being transmitted for cellular backhaul over satellite (CBoS). The terminal and gateway are, therefore, unable to provide the satellite GTP acceleration to the secure cellular traffic. Based on the foregoing, there is a need for an approach for applying satellite GTP acceleration to CBoS traffic while maintaining end to end IPsec encryption between the eNodeB and EPC.